
var m1 = document.querySelector("#m1");
var m2 = document.querySelector("#m2");
var m3 = document.querySelector("#m3");
var t2 = setInterval(function(){
    var t1=new Date();
    var t2=new Date('2019/9/8 21:00:00');
    var t3=t2-t1;
    //小时
    var t4=Math.floor(t3/(1000*60*60));
    var t5=t3%(1000*60*60);
    //分钟
    var t6=Math.floor(t5/(1000*60));

    var t7=t3%(1000*60);
    //秒
    var t8=Math.floor(t7/(1000));

    m1.innerHTML=t4;
    m2.innerHTML=t6;
    m3.innerHTML=t8;
});